Lifting device for moving goods between different levels

Abstract

A lifting device for moving two goods carrying platforms between different levels. The platforms are provided to perform a synchronous displacing movement in opposite directions relative to each other in one single path of travel. For the movement of the platforms transmission means are provided including two elongated flexible traction elements, preferably two chains. The one end of each element is fixed by anchoring to a stationary part of the lifting device and the other end is fixed to one of the platforms. A number of pulleys are provided to perform a linear reciprocating movement by means of driving means and thereby bring about a longitudinal change of a loop provided for each one of the traction elements and stretching around the respective pulley in opposite directions so that the loop which is connected with one of the platforms is lengthened, at the same time as the loop which is connected with the other platform is shortened and vice versa. Further means is provided to move aside the platform which is moving in the return direction in order to provide free passage for the platform, which is moving in the intended direction of goods transfer, which means comprises pivoting means for the platforms.

I claim: 
     
       1. Lifting device for the transfer of goods from a first level to a second level, comprising driving means, a frame having two guides, two platforms movable along said guides, pivoting means for supporting each platform on a respective guide and permitting each platform to be pivoted between a first position extending from its respective guide wherein it can carry goods and a second position adjacent to its respective guide, said guides being located relative to each other such that said platforms have substantially the same path of movement when being moved along said guides, power transmission means between said driving means and said platforms having for each platform an elongated flexible traction element, one end of which is attached to said frame and the other end to the respective platform, said traction element extending in a loop over a pulley, said pulley being operably connected to said driving means and actuated thereby to perform a reciprocating movement, the respective ends of the two traction elements attached to the respective platforms extending in opposite directions along the guides, whereby the platforms are moved in a synchronous displacing movement in opposite directions relative to each other in the path of movement along their respective guides when pulleys are displaced by means of the driving means, and means for pivoting said platforms between said positions whereby one of said platforms will be pivoted to said second position when the other platform is in the first position and moving in the opposite direction to provide free passage in the path of movement for said other platform, said pivoting means comprising a catching means provided to catch a part of said one platform at a distance from the pivoting axis of said one platform to impart a turning movement thereto when said axis is moved along the respective guide together with said one platform.